Every normal "blitz" will do, because they control the lighting for themselves. Just make sure you can set your camera up for using an external flash or the cam switches automatically to it when you put on the flash. BUT:If the S9600 has more than one central contact in the accessory shoe on top, chances are that the Fuji can control the flash TTL (consult your manual). Then you should definitely look after a compatible flash, because a TTL-flash has much better control over exposure!

.............30 seconds later............
As I looked it up on the german Metz site they say:
This camera (S9600) is equipped with an accessory shoe with centre contact for the connection of an external flash unit providing auto flash mode
And they go on to sugest the following flashes for your camera:
mecablitz 20 C-2, 76 MZ-5 digital, 45 CL-4 digital, 54 MZ-4/i, 44 MZ-2

So it seems you cannot use TTL-flash for your cam, just have to use standard automatic flash-mode. And as I said: This can be done by every flash...

Remember though to buy a strong flash, otherwise it will be only a weak update to your onboard flash. especially helpfull are flashes that can be zoomed like your lens. Because this can increase the reach of a flash considerably